<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>css盒子模型</title>
    <style>
        * {
            padding: 0;
            margin: 0;
        }
        .big {
            width: 100px;
            height: 100px;
            background-color: red;
            padding: 10px;
            margin: 20px;
            border: 5px solid blueviolet;
        }
        .small{
            width: 30px;
            height: 30px;
            background-color: green;
            padding: 10px 20px 30px 40px;
            border-bottom:2px  solid pink;
        }
        .box {
            height: 200px;
            width: 200px;
            background-color: green;
            padding: 10px;
            border: 5px solid #000;
        }
        .top{
            width: 100px;
            height: 100px;
            background-color: red;
            margin-bottom: 10px;
        }
        .bottom{
            width: 100px;
            height: 100px;
            background-color: green;
            margin-top: 20px;
        }
        .father{
            width: 200px;
            height: 200px;
            background-color: red;
            /* overflow:hidden; */
            float: left;
        }
        .son{
            width: 50px;
            height: 50px;
            background-color: green;
            margin-top: 20px;
        }
    </style>
</head>
<body>
    <!-- <div class="big">
        <div class="small">

        </div>
    </div> -->
    <!-- <div class="box"></div> -->
    <!-- 兄弟关系上下间距 -->
    <!-- <div class="top"></div>
    <div class="bottom"></div> -->

    <!-- 父子关系 -->
    <div class="father">
        <div class="son"></div>
    </div>
</body>
</html>